The National Weather Service office in Bismarck will stop issuing
Frost Advisories after Wednesday, September 30th...but will continue
to issue Freeze Watches and Freeze Warnings for western and central
North Dakota through October 15...which marks the end of the local
growing season...or until a hard freeze has been observed across
the area, whichever occurs first. A hard freeze is defined as temperatures
of 28 degrees Fahrenheit or lower, for a period of 3 or more hours.
A Freeze Watch will be considered appropriate when there is the
potential for temperatures to be 32 degrees or below for greater
than one hour over a geographically significant area during
the next 12 to 48 hours.
A Freeze Warning will be issued when the temperature is expected to
be 32 degrees or below for greater than one hour over a geographically
significant area during the next 24 hours. Significant damage to vegetation
is possible as a result of these conditions.